1. Field of the Invention
The present invention relates to a microscope system.
2. Description of the Related Art
In illumination operation control of a microscope, a technique of associating intensity of illumination light with change of an observation optical system is known. For example, when a zoom lens is changed to high magnification from low magnification, in general, the subject image darkens. In Jpn. Pat. Appln. KOKAI Publication No. 7-248450, a method is disclosed comprising: selecting a combination of optimum dimmer filters from a parameter table of a zoom magnification and light amount ratio; and switching IN/OUT the dimmer filter in an optical path to perform an automatic light adjustment control.
Moreover, in Jpn. Pat. Appln. KOKAI Publication No. 2000-137167, a method is disclosed comprising: picking up an image of a subject by an image pickup element; and controlling a power voltage supplied to a light source based on luminance information to perform light adjustment. Furthermore, in Jpn. Pat. Appln. KOKAI Publication No. 9-68742, a method is disclosed comprising: synchronizing an open/close period of a shutter of a camera with the illumination period of an LED for power saving.
Additionally, in the Jpn. Pat. Appln. KOKAI Publication No. 7-248450, a microscope system is disclosed including an objective lens and zoom mechanism. In this microscope system, the zoom mechanism includes means for storing a parameter of observation light amount, this parameter is referred to, and a dimmer member (ND filter) is controlled (combined insertion/detachment) so that the observation light amount before/after magnification change is kept constant.
However, in the Jpn. Pat. Appln. KOKAI Publication No. 7-248450, in order to switch IN/OUT the filter, the filter itself, a mechanism for driving the filter, and an electric control mechanism are required, and there are disadvantages that the apparatus is enlarged and the cost is raised.
Moreover, in the light adjustment control performed with the power voltage of the light source as in the Jpn. Pat. Appln. KOKAI Publication No. 2000-137167, an apparatus for calculating image data is required, the apparatus is similarly enlarged, and the cost is raised. Furthermore, since the dimmer control is a control to change the magnitude of the supply voltage, the color temperature of the light source changes with luminance. Even when the same subject is observed, but when the light adjustment is performed, the subject disadvantageously changes in color. Therefore, in microscope observation in which the state of a cell as the subject is judged from the color or shape of the cell, it is very difficult to perform the light adjustment in a method of adjusting the power voltage of the light source.
Furthermore, a product has heretofore been published in which an LED having low power consumption capability and high reliability is used as illumination. In general, the light adjustment control of the LED illumination include a supply voltage/current control, and a pulse control for changing conduction time of the supply current. However, for the supply voltage/current control, since the color temperature changes even in the LED, the control cannot be used in microscope observation.
Therefore, the light adjustment of the LED is performed by the pulse control, but a lighted period and extinguished period of the LED exist, and disadvantages are accordingly generated that a striped pattern is made in a screen in TV observation. To solve the problem, in Jpn. Pat. Appln. KOKAI Publication No. 9-68742, a method of synchronizing the shutter open/close period of the camera with the illumination period of the LED is disclosed.
However, in any of the above-described related arts, when natural energies such as sunlight are used as the light source for the subject to save electric power without using the light source of the microscope, relevance between image information and light source is eliminated, and therefore there is possibility that the disadvantage of the system by the light adjustment control is generated.
Moreover, in the Jpn. Pat. Appln. KOKAI Publication No. 7-248450, the light amount parameter needs to be stored in a PC memory or the like in order to maintain the observation light amount before/after the magnification change to be constant, and the image pickup element for detecting the light amount and electronic devices such as a storage memory are required. Furthermore, a housing, wiring, power supply, assembly adjustment, and the like are required for configuring a network of the electronic devices, and there is a problem that a very high cost is required.
On the other hand, for the method of controlling the power voltage to be supplied to the light source and performing the light adjustment as in the Jpn. Pat. Appln. KOKAI Publication No. 2000-137167, when the power voltage obtainable for the light adjustment reaches a maximum value, the light amount cannot be raised any more. However, this cannot be notified to an observer.
Moreover, in Jpn. Pat. Appln. KOKAI Publication No. 8-71085, a method is disclosed comprising: controlling an aperture area of an aperture diaphragm in accordance with the magnification of a zoom lens system to perform the light adjustment. Even in this case, at the maximum value of the aperture area of the aperture diaphragm, which can be obtained for the light adjustment, that is, in a state in which the light amount cannot be raised any more, this cannot be notified to the observer.
In this manner, the observer is not informed of anything even in the state in which the light amount is not adjusted. Therefore, when the light adjustment is impossible, there is a problem that the observer has an unnecessary feeling of insecurity.